> For the complete documentation index, see [llms.txt](https://docs.onum.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.onum.com/pipelines/actions/transformation/field-transformation/field-transformation-operations/utils/crc16-checksum.md).

# CRC16 checksum

## Description

This operation calculates a 16-bit Cyclic Redundancy Check (CRC) value for a given input. A **cyclic redundancy check (CRC)** is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data. 

The algorithm uses a fixed 16-bit polynomial to calculate a short "fingerprint" of the input data, resulting in a 16-bit (one-byte) checksum. This checksum can detect certain types of errors, like single-bit errors or burst errors up to 16 bits, by recalculating the checksum and comparing it with the original.

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## Data types

These are the input/output expected data types for this operation:

### Input data

`String` - Data you want to compute the CRC-16 checksum for.

### Output data <a href="#output-data" id="output-data"></a>

`String` - CRC-16 values of your input data.

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## Example

Suppose you want to calculate the CRC-16 of a specific set of data:

1. In your Pipeline, open the required [Action](/pipelines/actions.md) configuration and select the input **Field**.
2. In the **Operation** field, choose **CRC16 Checksum**.
3. Give your **Output field** a name and click **Save**. The operation will calculate the CRC16 codes for the strings in your input field. For example:

```
Input data - "hello 1234"

Output data - "57D4"
```

{% hint style="info" %}
You can try out operations with specific values using the **Input** field above the operation. You can enter the value in the example above and check the result in the **Output** field.
{% endhint %}